President Donald Trump appears to have painted himself into a corner: He must now follow up on his pledge of hitting North Korea with "fire and fury," or he risks further blowing U.S. credibility.

Kim Jong-un's regime said late on Tuesday that it may strike Guam. That came shortly after Trump warned Pyongyang it would face "power, the likes of which this world has never seen before" if the renegade state continued to threaten the U.S.

"If the red line he drew today was 'North Korea cannot threaten the U.S. anymore,' that line was crossed within an hour of him making that statement," said John Delury, associate professor of Chinese studies at Seoul-based Yonsei University.

The episode draws parallels to President Barack Obama's own geopolitical red line.

In 2013, the former leader said the use of chemical weapons in Syria's civil war would trigger an American military response. But when it happened, Obama failed to follow up on his promise — a move that critics, including Trump, said weakened Washington's position as a superpower.

"Trump is drawing a decisive red line for himself, we all think back to Obama's red line in Syria, which ultimately became an embarrassment for him," Peter Jennings, Australia's former deputy secretary in defense, told CNBC.

So, will Trump attack?

A U.S. offensive on North Korea isn't likely anytime soon, experts said, which means Trump just made the same mistake as his predecessor.

"Certainly, the president cannot back up a red line," said Delury, who is also a senior fellow at the Asia Society.

Defense secretary James Mattis and new chief of staff John Kelly are unlikely to sign off on any military action, so this may just be yet another example of "Trump being Trump and firing off his mouth," added Robert Kelly, associate professor at Pusan National University.

"In the short term, the Americans will wait and see if the latest sanctions change North Korea's behavior," said Jennings, currently executive director at the Australian Strategic Policy Institute.

But because Kim isn't expected to budge, the stalemate could result in the real risk of American preemptive action within six months, according to Jennings: "Just because it's a dangerous option doesn't mean it won't happen. It will be an act of last resort but looks like we're heading in that right direction."

US image dented

Trump's use of such incendiary rhetoric is seen further undermining the image of the world's largest economy.

"The more he doesn't follow-up on promises, the weaker America's image gets overseas...Trump is gaining a reputation for not being truthful," said Kelly.

Indeed, policy flip-flops from NATO to China have become a signature of the billionaire's administration.

"The problem with Trump's comments is there is no strategy behind them. They don't reflect a thought-out plan or discussions with allies, they just add more risk to an already risky situation," Jennings added.

Moreover, there was no real need for the president's Tuesday remark, according to Delury.

"Every single day, there's a [North Korean] threat on the U.S. or its allies. We haven't really seen any spectacular new level of threat," said Delury, who referred to North Korea's Guam warning as "standard operating procedure."

Instead of military might, officials should concentrate on the "freeze for freeze" deal, which remains the best option on the table, Delury continued.

Under the proposal, North Korea would temporarily freeze nuclear and missile tests in return for a reduced American military presence in the Korean Peninsula.

"It's a shame [Secretary of State] Rex Tillerson was in the same room as the North Korean foreign minister, who is a reasonable person, and that discussion didn't occur," Delury said. "Both sides need to probe to find a way to step back from the cliff and change these dynamics."